In diverse areas of therapy, including psychiatry, increasing interest in herbal medicine has been shown in recent years. Plants have a wide range of traditional uses, but only a few have been approved therapeutically. Moreover, to our knowledge, no bibliometric analyses on medicinal plants used in psychiatry have been carried out to date. We performed a bibliometric study on scientific publication related to phytotherapy in the psychiatry area during the period 1986-2006. Using the platform Embase.com, including the EMBASE and MEDLINE databases, we selected those documents including the descriptors plant*, herb*, phytotherapy*, phytomedicine*, pharmacognosy*, and psychiatry* (with all diagnostic criteria). The plants' indications were selected according to the PDR for Herbal Medicines. As a bibliometric indicator of the production, Price's Law was applied. Another indicator included was the national participation index (PI) for overall scientific production. A total of 21,409 original documents were obtained. Our data confirm a fulfillment of Price's Law related to scientific production on medicinal plants in Psychiatry. This was observed after we made a linear fit (y=135.08x-466.38; r=0.92) and another fit to an exponential curve (y=132.26e(0.1497x); r=0.99). The plants most widely mentioned in the psychiatric literature were St. John's wort (Hypericum perforatum L.; n=937) and ginkgo (Ginkgo biloba L.; n=694). The countries with the highest percentages of documents were the United States (29.44%), Germany (9.41%) and Japan (8.75%), and those with highest proportional PI were India (IPa=0.935) and China (IPa=0.721). Productivity on medicinal plants in the psychiatry area increased during the period 1986-2006. Nevertheless, documents about therapeutic herbs in this medical field are still relatively few in number.